Examples of websites using
Cooper BT
(Cooper BT is a serif font designed by Oswald Bruce Cooper and released by Bitstream in 1920. The family includes a variety of weights and styles)
with
Avenir
(Avenir is a sans-serif font designed by Adrian Frutiger and Nadine Chahine, released by Linotype in 1988. It features clean and modern letterforms and is available in multiple weights and styles)